Blockchain technology can be used to create a permanent, public, transparent ledger system for compiling data on sales, tracking digital use and payments to content creators, such as wireless users [65] or musicians.[66] In 2017, IBM partnered with ASCAP and PRS for Music to adopt blockchain technology in music distribution.[67] Imogen Heap's Mycelia service has also been proposed as blockchain-based alternative "that gives artists more control over how their songs and associated data circulate among fans and other musicians."[68][69] Everledger is one of the inaugural clients of IBM's blockchain-based tracking service.[70]
People believe that permissioned means that only a select group of people can access the data and that’s the security feature. But it’s not. Since there is no real user data on the blockchain, (you) as a member of the public, can’t verify the actual content of it. This means that data resides in a location where corruption can stay undetected and data can be easily modified. So why does it even exist? Mainly because of the phenomena known as “hype surfing”; essentially reusing old technology and strapping a blockchain sticker on it gets IBM salesmen a foot in the door to institutions who can’t evaluate the technology accurately in the first place. Unfortunately, even some teams doing public token offerings started to sell this deeply flawed approach to the public.

So if you want to create a more secure Sidechain, we would seriously need to have a look at incentivizing miners in other ways. These could include things such as the Sidechain raising outside funding from investors in order to pay the miners. Staggering mining award so miners have an incentive to keep mining as they will be paid later on rather than at the time or the Sidechain could issue its own mining award on top of the already existing transaction fees and essentially just become an Altcoin.
3) the argument ‘let’s harden internal IT as if it worked outside the firewall’ makes a ton of sense to me. We need to construct a lot of hoops for hackers to jump through, as permitter defense is not holding up anymore. And we need to make our systems anti-fragile. The blockchain data structure is a good tool, other P2P tools can be used too. Also, the blockchain has initiated a renaissance of crypto tech, like multisig, payment channels., HD wallets, hot-cold storage, and other innovations in key management.
Given all of this, it may seem like private blockchains are unquestionably a better choice for institutions. However, even in an institutional context, public blockchains still have a lot of value, and in fact this value lies to a substantial degree in the philosophical virtues that advocates of public blockchains have been promoting all along, among the chief of which are freedom, neutrality and openness. The advantages of public blockchains generally fall into two major categories:
If you’ve been keeping track of developments in the bitcoin industry, you’d know that the blockchain refers to the public ledger of transactions associated with the cryptocurrency. As the bitcoin ecosystem has grown in size and scale throughout the years, the blockchain has also increased considerably in length and storage size, prompting debates on whether or not to increase its block size limit.
In a cooperative consensus algorithm, there is a fixed number of voters. Voters cannot leave and join randomly. All voters know each other and every voter has only one vote. If the majority agree on the value of the data, then the system is working as designed. This can handle over 30,000 transactions per second. Scaling the number of voters can be an issue, because every vote proposed by a voter must be delivered to every other voter in the consortium.

NPD said the next step for retailers is to develop their own cryptocurrency to prevent customers from having to use credit cards when shopping online. NPD said the practice makes sense for the retailer, because if the customer could send the payment transfer via blockchain, it would avoid third-party clearing house fees retailers pay for processing card payments.
The words block and chain were used separately in Satoshi Nakamoto's original paper, but were eventually popularized as a single word, blockchain, by 2016. The term blockchain 2.0 refers to new applications of the distributed blockchain database, first emerging in 2014.[13] The Economist described one implementation of this second-generation programmable blockchain as coming with "a programming language that allows users to write more sophisticated smart contracts, thus creating invoices that pay themselves when a shipment arrives or share certificates which automatically send their owners dividends if profits reach a certain level."[1]

External Account, which stores ETH balance – This contains the address of the User that was created using the Web3.js API, e,g, personal.newAccount(…). These accounts are used for executing smart contract transactions. ETH is your incentive received for using your account to mine transactions. The address of the account is the public key, and the password of the account is the private key.
So, there is a kind of centralized authority that decides who has a right to contribute to and to audit the network. What is more – it’s possible to restrict viewing information stored on private blockchains. It might seem that in such conditions, a blockchain is no longer the blockchain as it lacks transparency and decentralization. Well, these remarks are fair, but only when the network is estimated from the outside. Within it, the rules remain the same as for public networks: it is still transparent for all the members.
Things get a bit more interesting when you replace the single custodian with a federation of notaries by way of a multisignature address. In this model, a federation of entities must sign-off on movements to and from the sidechain, so more parties must be compromised for a failure situation to unfold where the bitcoins frozen on the main chain are stolen.
Our Proof of Work tutorial talks about it in depth, but the best explanation might come from Satoshi Nakamoto himself. If the camps above start receiving messages that don’t agree, they rely on executing a Proof of Work. The Proof of Work is sufficiently complicated and requires significant computing power. Once one camp solves the Proof of Work, it broadcasts the results to the other camps. This message is now accepted in a chain of messages and the competing messages are dropped by the other camps.
Lisk es una plataforma open source en la que se pueden desarrollar y ejecutar smart contracts en forma de aplicaciones descentralizadas o DAPPS multiplataforma. Éstas, y como uno de los puntos fuertes de Lisk, son desarrolladas con, posiblemente, el lenguaje de programación más famoso y usado, Javascript. Aunque con un enfoque genérico, ya han empezado a aparecer algunas soluciones e interés en sectores concretos, como es el caso del Internet de las cosas que, junto a Chain of Things, están empezando a explotar.
At Iryo, we consider databases and blockchains that are not opened to the public to be insecure they, can easily be altered by the business running it, at their discretion and it goes against the ethos of the open and transparent cryptocurrency space. Designed to keep public out and introducing “trusted” middlemen, private chains forget that trusted third parties are security holes.
Las sidechains son otro de los conceptos más famosos entorno a Bitcoin, no los pierdas de vista. La teoría indica que permitirían añadir funcionalidades nuevas a Bitcoin, pero sin necesidad de modificar constantemente el código de éste, ya que la funcionalidad es desarrollada utilizando otra cadena de bloque para finalmente ser conectada a la de Bitcoin. Al mismo tiempo esto evitaría la saturación de una sola cadena de bloques, como actualmente ocurre, al utilizar cadenas diferentes para cada caso de uso.
To scale Blockchain, sidechain or childchain solutions cannot be undermined. Sidechains are separate Blockchains that are linked to the main Blockchain using a two-way peg. They are an auxiliary network that executes the complementary function of: faster transactions, lower transaction costs and greater scalability in terms of the number of transactions that can be supported in a network at a given time.

Byzantine fault tolerance (BFT) is what keeps the blockchain fundamentally secure. For simplicity, let’s say there were 100 nodes in a blockchain network (there are currently about 10,500 full Bitcoin nodes in the world). What happens when one node wants to tamper with the latest block and say other Bitcoin users sent him a whole bunch of Bitcoin when they really didn’t?
Cohen said Walmart also has a patent on drone delivery systems that facilitate orders in a cleaner way, track package contents, environmental conditions and location. Walmart supplier Coca-Cola is starting a pilot to use blockchain to identify inhumane labor conditions in its sugar supply chains. Coca-Cola plans to create a secure decentralized registry for workers and their contracts to help securely record their workers’ identities while providing a trail in case employers abuse their power.
Plasma, a project by Ethereum, uses this side chain concept. It encourages transactions to happen on side chains (or child chains). An authority governs each of the child chains. If the authority starts acting maliciously, anyone on the child chain can quit the child chain and take back their pegged assets on the main chain. It’s in its early stages of development but shows a lot of promise in handling some of Ethereum’s scalability issues.
Step back from the details for moment and consider what’s been described.  We now have a way to move coins from Bitcoin onto another platform (a sidechain) and move them back again.   That’s pretty much what we do when we move them to a wallet platform or an exchange.  The difference is that the “platform” they’ve been moved to is also a blockchain… so it has the possibility of decentralised security, visibility and to gain from other innovation in this space.

"I see quite a few use cases for private blockchains, and they definitely have their place. Traditional institutions won't switch to a completely public blockchain from one day to the other. A private blockchain is a great first step towards a more cryptographic future. The biggest advantages of private blockchains in comparison to centralized databases are the cryptographic auditing and known identities. Nobody can tamper with the data, and mistakes can be traced back. In comparison to a public blockchain it is much faster, cheaper and respects the company's privacy. As a conclusion, it's better to rely on a private blockchain than no cryptographic system at all. It has merits and pushes the blockchain terminology into the corporate world, making truly public blockchains a bit more likely for the future."